The frequently available creative dimensions for mobile in-app inventory in Display & Video 360 are 320×50, 320×480, 300×250, 728×90, and 768×1024.

• 320×50, 320×480, 336×280, 728×90, 768×1024
• 120×600, 320×50, 320×480, 300×250, 728×90
• 160×600, 320×50, 320×480, 336×280, 728×90
• 320×50, 320×480, 300×250, 728×90, 768×1024

The correct answer is: 320×50, 320×480, 300×250, 728×90, 768×1024

Explanation: These dimensions represent a range of ad sizes tailored for mobile and tablet screens, ensuring that ads fit seamlessly within various app environments. This versatility allows advertisers to effectively reach their target audience on mobile devices, optimizing engagement and visibility across different platforms and devices within the mobile ecosystem.

Read more here: https://support.google.com/displayvideo/answer/3017252